Reuters

Two and half years ago, Steve Stewart erected a 100-foot windmill at his Barstow, California home. Stewart is no eco-crusader, but he does know a good deal when he hears it.

Although the windmill cost $53,000, Stewart paid only $32,000 thanks to state tax incentives. His electric bill has zeroed out from $2,000 annually before, and most months he can even sell back surplus power to his local utility, Southern California Edison, netting as much as $500 per year.